Band-saw for sawing metal.



N0. 650,936. Patented .lune 5, |900. W. HARTMANN.

BAND SAW FOR SAWING METAL.

(Application Bled July 18, 1899.)

2 Sheets-Sheet I.

(No Model.)

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BAND sAw Fon sAwmG METAL.

(Application tiled July 18, 1899.) (un model.) 2 sheets-sheet 2.

No. 650,936?- Patented June 5, |900.

mz Nnnms PETERS co marc-umol. WASHINGTON. D. a

PATENT OFFICE.

WILHELM HARTMANN,

oF FULDA, GERMANY.

BAND-SAW FOR SAWING METAL.

SPECIFICATION forming part of Letters Patent No. 650,936, dated June 5, 1900. Application filed July 18, 1899. Serial No. 724,279. (No model.)

To all whom, t may concern:

Be it known that I, WILHELM HARTMANN, a subject of the Emperor of Germany, and a resident of Fulda, in the Empire of Germany, have invented a certain newand useful Band- Saw for Sawing Metals, of which the following is a full, clear, and exact specification.

My invention relates to a new and improved band-saw for sawing metals, and is constructed and operated as set forth in the following specification, of which the accompanying drawingsform an inseparable part.

In the drawings, in which similar letters refer throughout to similar parts, Figure l shows in side elevation my invention. Fig. 2 is a sectional vier. thereof on line A B of Fig. l.. Fig. 3 is a plan view of Fig. l.

Heretofore such machines have been so constructed that it was necessary to continuously advance the object being sawed against the band-saw. In lieu of band-sawing machines, machines were therefore generally employed having an oscillating or pendulumswung saw working upon the object stationarily fixed,the latter forms alone being susceptible of operation Without generating a frictional resistance of such degree as to make the machine unpractical. The fact that until my invention the sawing-machines having the object stationarily fixed were preferably provided with an oscillating or pendulum-swung saw is due to the cause that such alone were sufiiciently susceptible of continuously operating upon vand freely and simultaneously therewith advancing against the said object. It is therefore with the elimination of such drawbacks that I have invented a band-saw machine in which the object to be sawedis stationarily secured, while the band saw proper receives a regular cutting motion and in addition thereto and simultaneously therewith an automatic forward movement, the latter in all parts where friction is produced acting in such a manner that straight movement is avoided and exclusively-rotating parts are sliding in their journals,whereby an extremely easy movement is'obtained.

In the construction of my invention, therefore, I employ any desired frame, as C,Whicl1 has transversely mounted therein three parallel main shafts q, p, and p', while fastened to the forward side of said frame are suitable brackets u' and u, forming additional bearings for the forward-ends of the shafts aforesaid. These bearings q q p2 p2 have preferably bearing-balls therein, so as to reduce the friction in the axial movement of said shafts to a minimum, which latter have, as will be seen, a spirally-turning fore-andrear motion. Mounted on shaft q is a roller b, which, with rollers c and c, respectively mounted on shafts@ and p', carries the sawband a, adapted to saw an object fixed on atable or shelf adjacent thereto. Securely fastened to the frame C, projecting rearwardly therefrom, is a shaft-casing t, in which is mounted an axle s', carrying at its rear end a belt-wheel s and at its forward end a toothed wheel d, having any desired length, while mounted on shaft p is a toothed wheel d', meshing with wheel d aforesaid, and through which latter the shafts are given a rotary motion, thereby operating the band-saw a, and by which special construction of wheel cl its rotary movement can be imparted to wheel d at whatever position the shaft p may assume. Near the rearend of shaft q is asleeve r, having studs r therein, the latter in turn fitting in the prongs of a fork o', connected with a rod o, suitably mounted in bearings o2 in the said frame and extending at right angles to said shafts. To one end of said shaft ois connected a band n', which, passing over suitably-grooved wheels 'm m', has on its outer end a weight n, which as the latter descends throws arm o forward, thereby imparting a forward pressure to said shaft q; but since the said shaft is rapidly rotating its motion forward loses any direct forward movement and becomes a spiral or twisting action. VIn order to transmit this spiral action to shafts p and p', I employ racks lc and 7c', mounted on vertical axles 'L' t', Ywhich latter are journaled in any suitable supports connected with the frame of the machine. The side of rack c adjacent to shaft q is provided with a forked arm h, having slots g formed therein, and into which latter fit pins f, also carried on sleeve r aforesaid. On the adjoining sides of the racks 7c 7c are meshing toothed quadrants Z Z, through which connection, as will clearly be seen, the racks act together. Rack 7c is in turn in connection by suitably-forked arms with shafts p and p',

IOO

whence it will be seen that any forward movement imparted to shaft q will be simultaneously transmitted to the said latter shafts.

The operation and advantages of my invention will be clearly understood from the foregoing description and accompanying drawings, when taken in connection with the following statement. Desiring to saw a piece of metal, the same is secured to a suitable table or shelf and the machine thrown in gear, whence the power imparted by pulley-wheel s to axle s drives wheel d, the latter in turn rotating wheel d on shaft p, which carryingroller c operates the band-saw connected therewith, together with rollers c' and b and their respective shafts. Simultaneously thercwith, however, weight n continually draws band n' downwardly, thereby revolving rod o, which latter, through arm o', in connection with shaft q, and the latter, through the racks 7o and k', with their meshing quadrants, impart tio the said shafts a steady forward pressure, but which in place of developing a direct forward movement thereto is converted through the combination of the independ* ent rotary motion aforesaid therewith into a spirally-advancing forward action, thereby eliminating any frictional resistance arising through a straight movement of said shafts while rotating. By this adjustment the bandsaw a is continually advanced and held against the object, without., however, causing any heavy frictional resistance in the machine itself by such advancement.

Having now described my invention, what I claim as new, and desire to protect by Letters Patent, is-

1. In a new and improved band-saw the combination of a sawing-band with spiral actuated means for operating and advancing said sa wing-ba nd substantially as described.

2. In a new and improved band-saw, the combination of a sawing-band, rollers carrying said band, shaft-s in connection with the said rollers, means for giving said shafts a rotary movement, and other means for giving said shafts a lateral movement, both of said means being so arranged and combined as to generate a spiral movement in said shafts, substantially as described.

In a new and improved band-saw, the combination of a frame, ball-bearings therein, shafts mounted in said bearings, rollers on said shafts, a sawing-band on said rollers and means in connection with said shafts adapted to give the latter a spiral actuating movement, substantially as described.

4. In a new and improved band-saw, the combination of a frame, ball-bearing-journaled shafts therein, rollers on the forward ends of said shafts, a sawing-band on said rollers, a pulley-wheel in said frame, gearing connecting said wheel and said shafts and a weight-actuated rod in connection with said shafts, substantially as described.

5. In a new and improved band-saw, the combination of a frame, shafts journaled therein, rollers on said shafts, a sawing-band on said rollers, a rod suitably mounted in said frame, forked armen said rod provided with slots in the prongs of its fork, a sleeve on one of said shafts, studs on said sleeve entering said slots, racks in connection with said f rame,toothed quadrants on each of said racks meshing together, other forked arms on said racks engaging said shafts, a band connected with said rod, aweight on the outer end of said band and suitable mechanism for rotating said shafts substantially as described.

WTILIIELM HARTMANN.

Titncsscsz JEAN GRUND, SIMON W. HANAUER. 

